Over/Under/Perfectly-Expanded Nozzle Flow

Over/Under/Perfectly Expanded Nozzle Flow... 

A comparison of the theoretical exit pressure for an isen-tropic nozzle with the level of the ambient back-pressure. For isentropic exit pressures below the ambient, the flow is over-expanded for isentropic exit pressures exceeding the ambient value, the flow is under-expanded when the pressures are matched, the flow is perfectly expanded . 

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